The present invention is directed to medical systems, and more specifically, to systems, apparatus and methods for limiting the re-usage of medical probes, such as catheters and surgical probes.
Catheters, surgical probes and related probe devices (collectively referred to, hereinafter, as xe2x80x9cmedical probesxe2x80x9d or xe2x80x9cprobesxe2x80x9d) are used today in diagnostic and therapeutic medical procedures that require surgical or minimally invasive access to target tissue areas within interior regions of the body. During these procedures, a physician locates the distal end of the medical probe at the target site by, in the case of a catheter, steering the medical probe through a main vein or artery (typically, the femoral vein or artery), or, in the case of a surgical probe, advancing the medical probe through the surgical opening leading to the target site.
The physician then operates the medical probe to activate a functional component mounted at the probe distal end, thereby providing therapeutic treatment to and/or diagnosis of the interior region. Due to the potential of passing any of a variety of dangerous diseases from one patient to another, prudent consideration dictates that the reuse of such probes should be prevented or, at the least, minimized. Typically, medical probes that are re-used are sterilized between uses to kill any disease-causing agents and to remove any tissue that has collected on the medical probe during the previous use. Sterilization of used medical probes, however, is not fool-proof, and oftentimes ineffective when tissue located on the medical probe is not exposed to the full effect of the sterilization process. Thus, even a sterilized medical probe may pose a threat to patients.
Minimizing re-use of medical probes that provide therapy becomes even more critical. During the therapeutic process, it is important for the physician to control the therapeutic component at the probe distal end carefully and precisely, so that adverse damage to a therapeutic component of the medical probe does not occur. Sterilization of and re-use of therapeutic medical probes subjects the therapeutic component to mechanical, chemical and/or thermal stress, thus jeopardizing the control that the physician may have of the therapeutic component.
The need for careful and precise control over a therapeutic medical probe is especially critical during procedures that ablate tissue within the heart. These procedures, called electrophysiological therapy, are becoming more widespread for treating cardiac rhythm disturbances. When inside the desired chamber of the heart, the physician manipulates a steering mechanism to place one or more electrodes located at the distal end of the medical probe into direct contact with the heart tissue to be ablated. The physician then directs radio frequency energy from the electrodes through the tissue to an indifferent electrode, thereby ablating the tissue and forming a lesion. If the electrodes or the electrical wires connected thereto are worn or faulty, however, ablation may be ineffective and, in the worst case, may cause charring of the heart tissue.
Preventing or limiting re-usage of medical probes, while still allowing legitimate use of these probes, is made difficult by a possible scenario wherein the physician uses the medical probe, temporarily disconnects the probe from the control unit, and reconnects the probe to the control unit to continue the procedure. Thus, there is a danger of deeming the continued procedure to be re-usage of the medical probe, which may result in the probe being rendered prematurely inoperable.
Thus, it would be desirable to provide an improved medical system for minimizing the re-usage of medical probes, while still allowing legitimate use of these probes.
The present invention is directed to improved apparatus and methods for limiting the usage of medical probes, such as, e.g., catheters and surgical probes.
In a preferred method performed in accordance with a first aspect of the invention, the sterilization of a medical probe is monitored by detecting an environmental condition to which the medical probe is exposed, electronically storing a probe sterilization indicator with the medical probe if the detected environmental condition indicates exposure of the medical probe to a sterilization cycle and determining the presence of the probe sterilization indicator. By way of non-limiting example, either temperature, moisture, pressure and/or a chemical is the detected environmental condition. The medical probe is conditionally operated based on the presence of the probe sterilization indicator. The operation of the medical probe may also be based on the presence of a probe usage indicator, which indicates if the medical probe has been previously operated.
In another preferred method performed in accordance with a further aspect of the invention, the usage of a medical probe is limited by detecting an environmental condition to which the medical probe is exposed, electronically storing a probe sterilization indicator in the medical probe if the detected environmental condition indicates exposure of the medical probe to a sterilization cycle, determining a presence of the medical probe indicator, and conditionally operating the medical probe based on the presence of the probe sterilization indicator. A probe usage indicator indicating that the medical probe has been operated can be stored in the medical probe. Conditional operation of the medical probe can also be based on the probe usage indicator. Alternatively, an estimated probe sterilization date or probe manufacture date can be stored in the medical probe when the medical probe is manufactured, and an actual probe sterilization date can be stored in the medical probe upon actual sterilization of the medical probe. Conditional operation of the medical probe can be based on the estimated probe sterilization date and the actual probe sterilization date. By way of non-limiting example, the medical probe can be prevented from being operated if the actual probe sterilization date is later than the estimated probe sterilization date. Optionally, the actual probe sterilization date can be used to enforce the shelf-life of the medical probe. By way of non-limiting example, operation of the medical probe can be prevented if the difference between the actual probe sterilization date and a reference date, such as, e.g., the current date, is greater than a predetermined period of time.
In a preferred embodiment constructed in accordance with still another aspect of the invention, a control unit for connection to a medical probe having electronic storage componentry, comprises control circuitry configured to electrically couple to the electronic storage componentry for reading data from the electronic storage componentry, and for conditionally operating the medical probe based on a presence of a probe sterilization indicator in the data. By way of non-limiting example, the preferred embodiment of the control unit is an RF generator having a microprocessor as the control circuitry. The microprocessor is configured for conditionally operating the medical probe based on the presence of the probe sterilization indicator. The microprocessor can also be configured for conditionally operating the medical probe based on the presence of a probe usage indicator indicating previous operation of the medical probe. When the medical probe is operated, and more preferably, when the medical probe is effectively operated, the probe usage indicator is stored in the electronic storage componentry and the probe sterilization indicator is cleared.
In another preferred embodiment constructed in accordance with still a further aspect of the invention, a medical probe includes an elongate member carrying electronic storage componentry configured for detecting an environmental condition to which the medical probe is exposed and storing a probe sterilization indicator in the medical probe if the detected environmental condition indicates exposure of the medical probe to a sterilization cycle. By way of non-limiting example, in the preferred embodiment, the electronic storage component is a non-volatile storage component, such as, e.g., nonvolatile RAM and a battery. Alternatively, the non-volatile storage components can comprise other components that have environmental sensing capabilities. For example, the non-volatile component can comprise an electrolytic sensor or chemfet.